Military vehicle

ABSTRACT

A military vehicle includes a front axle, a rear axle, a front differential coupled to the front axle, and a transaxle coupled to the rear axle and the front differential. The transaxle includes an internal mechanical disconnect that facilitates mechanically decoupling the transaxle from the front differential.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 17/398,557, filed Aug. 10, 2021, which is a continuation of U.S. patent application Ser. No. 16/529,508, filed Aug. 1, 2019, which is a continuation of U.S. patent application Ser. No. 15/599,174, filed May 18, 2017, which is a continuation of U.S. patent application Ser. No. 14/724,279, filed May 28, 2015, which is a continuation of U.S. patent application Ser. No. 13/841,686, filed Mar. 15, 2013, which claims the benefit of U.S. Provisional Patent Application No. 61/615,812, filed Mar. 26, 2012, all of which are incorporated herein by reference in their entireties.

BACKGROUND

The present application relates to vehicles. In particular, the present application relates to the structural frame assembly of a military vehicle.

A military vehicle may be used in a variety of applications and conditions. These vehicles generally include a number of vehicle systems or components (e.g., a cab or body, a drive train, etc.). The military vehicle may also include various features and systems as needed for the specific application of the vehicle (e.g., a hatch, a gun ring, an antenna, etc.). Proper functioning and arrangement of the vehicle systems or components is important for the proper functioning of the vehicle.

Traditional military vehicles include a cab assembly coupled to a pair of frame rails that extend along the length of the vehicle. The drive train, engine, and other components of the vehicle are coupled to the frame rails. Such vehicles may be transported by securing lifting slings to the frame rails and applying a lifting force (e.g., with a crane, with a helicopter, etc.). As the frame rails are the primary structure of the vehicle, a lifting force applied to a rear portion and a front portion elevate the vehicle from a ground surface. In such a configuration, the components of the vehicle must be coupled to the structural frame rails thereby requiring sequential assembly.

SUMMARY

One embodiment relates to a military vehicle. The military vehicle includes a front axle, a rear axle, a front differential coupled to the front axle, and a transaxle coupled to the rear axle and the front differential. The transaxle includes an internal mechanical disconnect that facilitates mechanically decoupling the transaxle from the front differential.

Another embodiment relates to a military vehicle. The military vehicle includes a front axle, a rear axle, a prime mover, a front differential coupled to the front axle, a transaxle coupled to the prime mover, the rear axle, and the front differential, and an actuator. The transaxle includes an internal mechanical disconnect. The actuator is positioned at a rear of the vehicle. The actuator facilitates engaging the internal mechanical disconnect to mechanically decouple the transaxle from the front differential.

Still another embodiment relates to a military vehicle. The military vehicle includes a front axle, a rear axle, a plurality of tractive elements coupled to the front axle and the rear axle, a front differential coupled to the front axle, a transaxle coupled to the rear axle and the front differential, and a brake system. The brake system includes a brake, a brake housing, a piston, a rod, a resilient member, and an air-to-hydraulic intensifier. The brake is configured to facilitate braking one of the plurality of tractive elements. The brake housing defines an inner volume. The piston separates the inner volume into a first chamber and a second chamber. The rod extends through an end of the brake housing and is coupled to the piston. The rod is positioned to selectively engage with the brake to inhibit movement of the one of the plurality of tractive elements. The resilient member is positioned within the inner volume and configured to generate a brake biasing force against the piston such that the rod is biased into engagement with the brake. The air-to-hydraulic intensifier is coupled to the brake housing. The air-to-hydraulic intensifier is configured to receive a supply of air and provide a hydraulic fluid to the brake housing based on the supply of air to overcome the brake biasing force to disengage the rod from the brake to permit movement of the one of the plurality of tractive elements.

The invention is capable of other embodiments and of being carried out in various ways. Alternative exemplary embodiments relate to other features and combinations of features as may be recited in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will become more fully understood from the following detailed description, taken in conjunction with the accompanying figures, wherein like reference numerals refer to like elements, in which:

FIGS. 1-2 are a perspective views of a vehicle, according to an exemplary embodiment.

FIG. 3 is a schematic side view of the vehicle of FIG. 1 , according to an exemplary embodiment.

FIGS. 4-6 are perspective views of a vehicle having a passenger capsule, a front module, and a rear module, according to an exemplary embodiment.

FIGS. 7-9 are perspective views of a vehicle having a passenger capsule, a front module, and a rear module, according to an alternative embodiment.

FIG. 10A is a schematic sectional view of a vehicle having at least a portion of a suspension system coupled to a transaxle, according to an exemplary embodiment, and FIG. 10B is schematic sectional view of a vehicle having a passenger capsule, according to an exemplary embodiment.

FIG. 11 is schematic view of a braking system for a vehicle, according to an exemplary embodiment.

FIG. 12 is schematic view of a vehicle control system, according to an exemplary embodiment.

DETAILED DESCRIPTION

Before turning to the figures, which illustrate the exemplary embodiments in detail, it should be understood that the present application is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology is for the purpose of description only and should not be regarded as limiting.

Referring to FIGS. 1-3 , a military vehicle 1000 includes a hull and frame assembly 100, an armor assembly 200, an engine 300, a transmission 400, a transaxle 450, wheel and tire assemblies 600, a braking system 700, a fuel system 800, and a suspension system 460 coupling the hull and frame assembly 100 to the wheel and tire assemblies 600. According to an exemplary embodiment, the military vehicle 1000 includes a power generation system 900. As shown in FIG. 1 , the military vehicle 1000 also includes a trailer 1100.

Hull and Frame Assembly

Referring to FIG. 2 , the hull and frame assembly 100 includes a passenger capsule, shown as passenger capsule 110, a front module, shown as front module 120, and a rear module, shown as rear module 130. According to an exemplary embodiment, the front module 120 and the rear module 130 are coupled to the passenger capsule 110 with a plurality of interfaces. As shown in FIG. 2 , the front module 120 includes a front axle having wheel and tire assemblies 600.

According to an exemplary embodiment, the rear module 130 includes a body assembly, shown as bed 132. As shown in FIG. 2 , front module 120 also includes a body panel, shown as hood 122. In some embodiments, the hood 122 partially surrounds the engine of military vehicle 1000. The hood 122 is constructed of a composite material (e.g., carbon fiber, fiberglass, a combination of fiberglass and carbon fiber, etc.) and sculpted to maximize vision and clear under-hood components. According to an alternative embodiment, the hood 122 is manufactured from another material (e.g., steel, aluminum, etc.). The front portion of hood 122 mounts to a lower cooling package frame, and the upper mount rests on the windshield wiper cowl. This mounting configuration reduces the number and weight of components needed to mount the hood 122. The Oshkosh Corporation® logo is mounted to a frame structure, which is itself mounted directly to the cooling package. The hood 122 includes bumperettes 123 that provide mounting locations for antennas (e.g., a forward-facing TED jammer, a communications whip antenna, etc.). In one embodiment, the bumperettes 123 and front of the hood 122 may be reinforced (e.g., with structural fibers, structural frame members, etc.) to become structural members intended to prevent damage to the tire assemblies 600. In an alternative embodiment, the bumperettes 123 may be crushable members or “break away” members that disengage upon impact to prevent interference between the bumperettes 123 and tire assemblies 600 in the event of a front impact.

Referring next to the exemplary embodiment shown in FIGS. 4-9 , the military vehicle 1000 includes passenger capsule 110, front module 120, and rear module 130. As shown in FIGS. 4 and 7 , passenger capsule 110 includes a structural shell 112 that forms a monocoque hull structure. Monocoque refers to a form of vehicle construction in which the vehicle body and chassis form a single unit. The structural shell 112 is configured to provide a structural load path between front module 120 and rear module 130 of military vehicle 1000 (e.g., during driving, a lifting operation, during a blast event, etc.). According to an exemplary embodiment, the structural shell 112 includes a plurality of integrated armor mounting points configured to engage a supplemental armor kit (e.g., a “B-Kit,” etc.). The structural shell 112 is rigidly connected to the rest of the powertrain, drivetrain, suspension, and major systems such that they all absorb blast energy during a blast event, according to an exemplary embodiment. According to an exemplary embodiment, the structural shell 112 is large enough to contain four-passengers in a standard two-by-two seating arrangement and four doors 104 are rotatably mounted to the structural shell 112. According to the alternative embodiment shown in FIGS. 7-9 , two doors 104 are coupled to structural shell 112. Front module 120 and rear module 130 are configured to engage a passenger capsule having either two doors or four doors, according to an exemplary embodiment. As shown in FIGS. 6 and 9 , the structural shell 112 includes a first end 114 and a second end 116.

According to an exemplary embodiment, front module 120 includes a subframe having a first longitudinal frame member 124 and a second longitudinal frame member 126. As shown in FIGS. 4-9 , an underbody support structure 128 is coupled to the first longitudinal frame member 124 and the second longitudinal frame member 126. According to an exemplary embodiment, the first longitudinal frame member 124 and the second longitudinal frame member 126 extend within a common plane (e.g., a plane parallel to a ground surface). The underbody support structure 128 is coupled to the first end 114 of structural shell 112 and includes a plurality of apertures 129 that form tie down points. In some embodiments, an engine for the military vehicle 1000 is coupled to the first longitudinal frame member 124 and the second longitudinal frame member 126. In other embodiments, the front module 120 includes a front axle assembly coupled to the first longitudinal frame member 124 and the second longitudinal frame member 126.

As shown in FIGS. 4 and 6 , rear module 130 includes a subframe having a first longitudinal frame member 134 and a second longitudinal frame member 136. As shown in FIGS. 4-9 , an underbody support structure 138 is coupled to the first longitudinal frame member 134 and the second longitudinal frame member 136. According to an exemplary embodiment, the first longitudinal frame member 134 and the second longitudinal frame member 136 extend within a common plane (e.g., a plane parallel to a ground surface). The underbody support structure 138 is coupled to the second end 116 of structural shell 112, the first longitudinal frame member 134, and the second longitudinal frame member 136. According to an exemplary embodiment, the first longitudinal frame member 134 and the second longitudinal frame member 136 include a plurality of apertures 139 that form tie down points. In some embodiments, a transaxle 450 or a differential for the military vehicle 1000 is coupled to at least one of the first longitudinal frame member 134 and the second longitudinal frame member 136. In other embodiments, the rear module 130 includes a rear axle assembly coupled to the first longitudinal frame member 134 and the second longitudinal frame member 136.

The subframes of the front module 120 and the rear module 130 may be manufactured from High Strength Steels (HSS), high strength aluminum, or another suitable material. According to an exemplary embodiment, the subframes feature a tabbed, laser cut, bent and welded design. In other embodiments, the subframes may be manufactured from tubular members to form a space frame. The subframe may also include forged, rather than fabricated or cast frame sections to mitigate the stress, strains, and impact loading imparted during operation of military vehicle 1000. Aluminum castings may be used for various cross member components where the loading is compatible with material properties. Low cost aluminum extrusions may be used to tie and box structures together.

The structural shell 112 and the subframes of the front module 120 and the rear module 130 are integrated into the hull and frame assembly 100 to efficiently carry chassis loading imparted during operation of the military vehicle 1000, during a lift event, during a blast event, or under still other conditions. During a blast event, conventional frame rails can capture the blast force transferring it into the vehicle. Military vehicle 1000 replaces conventional frame rails and instead includes passenger capsule 110, front module 120, and rear module 130. The passenger capsule 110, front module 120, and rear module 130 provides a vent for the blast gases (e.g., traveling upward after the tire triggers an IED) thereby reducing the blast force on the structural shell 112 and the occupants within passenger capsule 110. Traditional frame rails may also directly impact (i.e. contact, engage, hit, etc.) the floor of traditional military vehicles. Military vehicle 1000 that includes passenger capsule 110, front module 120, and rear module 130 does not include traditional frame rails extending along the vehicle's length thereby eliminating the ability for such frame rails to impact the floor of the passenger compartment. Military vehicle 1000 that includes a passenger capsule 110, front module 120, and rear module 130 also has an improved strength-to-weight performance, abuse tolerance, and life-cycle durability.

According to an exemplary embodiment, the doors 104 incorporate a combat lock mechanism. In some embodiments, the combat lock mechanism is controlled through the same handle that operates the automotive door latch system, allowing a passenger to release the combat locks and automotive latches in a single motion for quick egress. The doors 104 also interface with an interlocking door frame 109 defined within structural shell 112 adjacent to the latch, which helps to keep the doors 104 closed and in place during a blast even. Such an arrangement also distributes blast forces between a front and a rear door mounting and latching mechanism thereby improving door functionality after a blast event.

Lift Structure

According to an exemplary embodiment, the military vehicle 1000 may be transported from one location to another in an elevated position with respect to a ground surface (e.g., during a helicopter lift operation, for loading onto or off a ship, etc.). As shown in FIGS. 4-9 , military vehicle 1000 includes a lift structure 140 coupled to the front module 120. According to an exemplary embodiment, the lift structure includes a first protrusion 144 extending from the first longitudinal frame member 124, a second protrusion 146 coupled to the second longitudinal frame member 126, and a lateral frame member 148 extending between the first protrusion 144 and the second protrusion 146. As shown in FIGS. 4-9 , the first protrusion 144 and the second protrusion 146 extend along an axis that is generally orthogonal (e.g., within 20 degrees of an orthogonal line) to a common plane within which the first longitudinal frame member 134 and the second longitudinal frame member 126 extend. As shown in FIGS. 5-6 and 8-9 , the first protrusion 144 defines a first aperture 145, and the second protrusion 146 defines a second aperture 147. The first aperture 145 and the second aperture 147 define a pair of front lift points. An operator may engage the front lift points with a sling, cable, or other device to elevate military vehicle 1000 from a ground surface (e.g., for transport).

According to an exemplary embodiment, the hood 122 defines an outer surface (e.g., the surface exposed to a surrounding environment) and an inner surface (e.g., the surface facing the first longitudinal frame member 124 and the second longitudinal frame member 126). It should be understood that the outer surface is separated from the inner surface by a thickness of the hood 122. As shown schematically in FIGS. 4, 6-7, and 9 , first protrusion 144 and second protrusion 146 extend through a first opening and a second opening defined within the hood 122. According to an exemplary embodiment, the pair of front lift points is positioned along the outer surface of the hood 122 (e.g., to provide preferred sling angles, to facilitate operator access, etc.).

According to an exemplary embodiment, the first longitudinal frame member 124 and the second longitudinal frame member 126 are coupled to the first end 114 of the structural shell 112 with a plurality of interfaces. Such interfaces may include, by way of example, a plurality of fasteners (e.g., bolts, rivets, etc.) extending through corresponding pads coupled to the front module 120 and the structural shell 112. According to an exemplary embodiment, a lifting force applied to the pair of front lift points is transmitted into the structural shell of the passenger capsule to lift the vehicle.

In some embodiments, the military vehicle 1000 includes breakaway sections designed to absorb blast energy and separate from the remaining components of military vehicle 1000. The blast energy is partially converted into kinetic energy as the breakaway sections travel from the remainder of military vehicle 1000 thereby reducing the total energy transferred to the passengers of military vehicle 1000. According to an exemplary embodiment, at least one of the front module 120 and the rear module 130 are breakaway sections. Such a military vehicle 1000 includes a plurality of interfaces coupling the front module 120 and the rear module 130 to passenger capsule 110 that are designed to strategically fail during a blast event. By way of example, at least one of the plurality of interfaces may include a bolted connection having a specified number of bolts that are sized and positioned (e.g., five 0.5 inch bolts arranged in a pentagon, etc.) to fail as an impulse force is imparted on front module 120 or rear module 130 during a blast event. In other embodiments, other components of the military vehicle 1000 (e.g., wheel, tire, engine, etc.) are breakaway sections.

Referring again to the exemplary embodiment shown in FIGS. 4-6 , the military vehicle 1000 may be lifted by a pair of apertures defined within a pair of protrusions 115. The apertures define a pair of rear lift points for military vehicle 1000. As shown in FIG. 5 , the pair of protrusions 115 extend from opposing lateral sides of the structural shell 112. It should be understood that a lifting force applied directly to the pair of protrusions 115 may, along with the lifting force applied to lift structure 140, elevate the military vehicle 1000 from a ground surface. The structural shell 112 carries the loading imparted by the lifting forces applied to the lift structure 140 (e.g., through the plurality of interfaces) and the pair of protrusions 115 to elevate the military vehicle 1000 from the ground surface without damaging the passenger capsule 110, the front module 120, or the rear module 130.

Armor Assembly

Referring next to the exemplary embodiment shown in FIG. 10B, the armor assembly 200 includes fabricated subassemblies (roof, floor, sidewalls, etc.) that are bolted together. The armor assembly 200 may be manufactured from steel or another material. The armor assembly 200 provides a robust and consistent level of protection by using overlaps to provide further protection at the door interfaces, component integration seams, and panel joints.

In another embodiment, the armor assembly 200 further includes a 360-degree modular protection system that uses high hard steel, commercially available aluminum alloys, ceramic-based SMART armor, and two levels of underbody mine/improved explosive device (“TED”) protection. The modular protection system provides protection against kinetic energy projectiles and fragmentation produced by IEDs and overhead artillery fire. The modular protection system includes two levels of underbody protection. The two levels of underbody protection may be made of an aluminum alloy configured to provide an optimum combination of yield strength and material elongation. Each protection level uses an optimized thickness of this aluminum alloy to defeat underbody mine and IED threats.

Referring now to FIG. 10B, the armor assembly 200 also includes a passenger capsule assembly 202. The passenger capsule assembly 202 includes a V-shaped belly deflector 203, a wheel deflector, a floating floor, footpads 206 and energy absorbing seats 207. The V-shaped belly deflector 203 is integrated into the sidewall. The V-shaped belly deflector 203 is configured to mitigate and spread blast forces along a belly. In addition, the wheel deflector mitigates and spreads blast forces. The “floating” floor utilizes isolators and standoffs to decouple forces experienced in a blast event from traveling on a direct load path to the passenger's lower limbs. The floating floor mounts to passenger capsule assembly 202 isolating the passenger's feet from direct contact with the blast forces on the belly. Moreover, footpads protect the passenger's feet. The energy absorbing seats 207 reduce shock forces to the occupants' hips and spine through a shock/spring attenuating system. The modular approach of the passenger capsule assembly 202 provides increased protection with the application of perimeter, roof and underbody add on panels. The components of the passenger capsule assembly 202 mitigate and attenuate blast effects, allow for upgrades, and facilitate maintenance and replacements.

The passenger capsule assembly 202 further includes a structural tunnel 210. For load purposes, the structural tunnel 210 replaces a frame or rail. The structural tunnel 210 has an arcuately shaped cross section and is positioned between the energy absorbing seats 207. The configuration of the structural tunnel 210 increases the distance between the ground and the passenger compartment of passenger capsule assembly 202. Therefore, the structural tunnel 210 provides greater blast protection from IEDs located on the ground because the IED has to travel a greater distance in order to penetrate the structural tunnel 210.

Engine

The engine 300 is a commercially available internal combustion engine modified for use on military vehicle 1000. The engine 300 includes a Variable Geometry Turbocharger (VGT) configured to reduce turbo lag and improve efficiency throughout the engine 300's operating range by varying compressor housing geometry to match airflow. The VGT also acts as an integrated exhaust brake system to increase engine braking capability. The VGT improves fuel efficiency at low and high speeds and reduces turbo lag for a quicker powertrain response.

The engine 300 includes a glow plug module configured to improve the engine 300 cold start performance. In some embodiments, no ether starting aid or arctic heater is required. The glow plug module creates a significant system cost and weight reduction.

In addition, engine 300 includes a custom oil sump pickup and windage tray, which ensures constant oil supply to engine components. The integration of a front engine mount 472 into a front differential gear box 470 eliminates extra brackets, reduces weight, and improves packaging. Engine 300 may drive an alternator/generator, a hydraulic pump, a fan, an air compressor and/or an air conditioning pump. Engine 300 includes a top-mounted alternator/generator mount in an upper section of the engine compartment that allows for easy access to maintain the alternator/generator and forward compatibility to upgrade to a higher-power export power system. A cooling package assembly is provided to counteract extreme environmental conditions and load cases.

According to an exemplary embodiment, the military vehicle 1000 also includes a front engine accessory drive (FEAD) that mounts engine accessories and transfers power from a front crankshaft dampener/pulley to the accessory components through a multiple belt drive system. According to an exemplary embodiment, the FEAD drives a fan, an alternator, an air conditioning pump, an air compressor, and a hydraulic pump. There are three individual belt groups driving these accessories to balance the operational loads on the belt as well as driving them at the required speeds. A top-mounted alternator provides increased access for service and upgradeability when switching to the export power kit (e.g., an alternator, a generator, etc.). The alternator is mounted to the front sub frame via tuned isolators, and driven through a constant velocity (CV) shaft coupled to a primary plate of the FEAD. This is driven on a primary belt loop, which is the most inboard belt to the crank dampener. No other components are driven on this loop. A secondary belt loop drives the hydraulic pump and drive through pulley. This loop has one dynamic tensioner and is the furthest outboard belt on the crankshaft dampener pulley. This belt loop drives power to a tertiary belt loop through the drive through pulley. The tertiary belt loop drives the air conditioning pump, air compressor, and fan clutch. There is a single dynamic tensioner on this loop, which is the furthest outboard loop of the system.

Transmission, Transfer Case, Differentials

Military vehicle 1000 includes a commercially available transmission 400. Transmission 400 also includes a torque converter configured to improve efficiency and decrease heat loads. Lower transmission gear ratios combined with a low range of an integrated rear differential/transfer case provide optimal speed for slower speeds, while higher transmission gear ratios deliver convoy-speed fuel economy and speed on grade. In addition, a partial throttle shift performance may be refined and optimized in order to match the power outputs of the engine 300 and to ensure the availability of full power with minimal delay from operator input. This feature makes the military vehicle 1000 respond more like a high performance pickup truck than a heavy-duty armored military vehicle.

The transmission 400 includes a driver selectable range selection. The transaxle 450 contains a differential lock that is air actuated and controlled by switches on driver's control panel. Indicator switches provide shift position feedback and add to the diagnostic capabilities of the vehicle. Internal mechanical disconnects 452 within the transaxle 450 allow the vehicle to be either flat towed or front/rear lift and towed without removing the drive shafts. Mechanical air solenoid over-rides 454 are easily accessible at the rear of the vehicle. Once actuated, no further vehicle preparation is needed. After the recovery operation is complete, the drive train is re-engaged by returning the air solenoid mechanical over-rides to the original positions.

The transaxle 450 is designed to reduce the weight of the military vehicle 1000. The weight of the transaxle 450 was minimized by integrating the transfercase 452 and rear differential 454 into a single unit, selecting an optimized gear configuration, and utilizing high strength structural aluminum housings 456. By integrating the transfercase 452 and rear differential 454 into transaxle 450 thereby forming a singular unit, the connecting drive shaft and end yokes traditionally utilized between to connect them has been eliminated. Further, since the transfercase and rear carrier have a common oil sump and lubrication system, the oil volume is minimized and a single service point is used. The gear configuration selected minimizes overall dimensions and mass providing a power dense design. The housings are cast from high strength structural aluminum alloys and are designed to support both the internal drive train loads as well as structural loads from the suspension system 460 and frame, eliminating the traditional cross member for added weight savings. According to the exemplary embodiment shown in FIG. 10A, at least a portion of the suspension system 460 (e.g., the upper control arm 462, the lower control arm 464, both the upper and lower control arms 462, 464, a portion of the spring 466, damper 468, etc.) is coupled to the transaxle 450. Such coupling facilitates assembly of military vehicle 1000 (e.g., allowing for independent assembly of the rear axle) and reduces the weight of military vehicle 1000. The front axle gearbox also utilizes weight optimized gearing, aluminum housings, and acts as a structural component supporting internal drive train, structural, and engine loads as well. The integrated transfercase allows for a modular axle design, which provides axles that may be assembled and then mounted to the military vehicle 1000 as a single unit. An integral neutral and front axle disconnect allows the military vehicle 1000 to be flat towed or front/rear lift and towed with minimal preparation. Further, the integrated design of the transaxle 450 reduces the overall weight of the military vehicle 1000. The transaxle 450 further includes a disconnect capability that allows the front tire assemblies 600 to turn without rotating the entire transaxle 450. Housings of the front and rear gearbox assembly are integrated structural components machined, for example, from high strength aluminum castings. Both front and rear gearbox housings provide stiffness and support for rear module 130 and the components of the suspension system 460.

Suspension

The military vehicle 1000 includes a suspension system 460. The suspension system 460 includes high-pressure nitrogen gas springs 466 calibrated to operate in tandem with standard low-risk hydraulic shock absorbers 468, according to an exemplary embodiment. In one embodiment, the gas springs 466 include a rugged steel housing with aluminum end mounts and a steel rod. The gas springs 466 incorporate internal sensors to monitor a ride height of the military vehicle 1000 and provide feedback for a High Pressure Gas (HPG) suspension control system. The gas springs 466 and HPG suspension control system are completely sealed and require no nitrogen replenishment for general operation.

The HPG suspension control system adjusts the suspension ride height when load is added to or removed from the military vehicle 1000. The control system includes a high pressure, hydraulically-actuated gas diaphragm pump, a series of solenoid operated nitrogen gas distribution valves, a central nitrogen reservoir, a check valve arrangement and a multiplexed, integrated control and diagnostics system.

The HPG suspension control system shuttles nitrogen between each individual gas spring and the central reservoir when the operator alters ride height. The HPG suspension control system targets both the proper suspension height, as well as the proper gas spring pressure to prevent “cross-jacking” of the suspension and ensure a nearly equal distribution of the load from side to side. The gas diaphragm pump compresses nitrogen gas. The gas diaphragm pump uses a lightweight aluminum housing and standard hydraulic spool valve, unlike more common larger iron cast industrial stationary systems not suitable for mobile applications.

The suspension system 460 includes shock absorbers 468. In addition to their typical damping function, the shock absorbers 468 have a unique cross-plumbed feature configured to provide auxiliary body roll control without the weight impact of a traditional anti-sway bar arrangement. The shock absorbers 468 may include an equal area damper, a position dependent damper, and/or a load dependent damper.

Brakes

The braking system 700 includes a brake rotor and a brake caliper. There is a rotor and caliper on each wheel end of the military vehicle 1000, according to an exemplary embodiment. According to an exemplary embodiment, the brake system includes an air over hydraulic arrangement. As the operator presses the brake pedal, and thereby operates a treadle valve, the air system portion of the brakes is activated and applies air pressure to the hydraulic intensifiers. According to an exemplary embodiment, military vehicle 1000 includes four hydraulic intensifiers, one on each brake caliper. The intensifier is actuated by the air system of military vehicle 1000 and converts air pressure from onboard military vehicle 1000 into hydraulic pressure for the caliper of each wheel. The brake calipers are fully-integrated units configured to provide both service brake functionality and parking brake functionality.

To reduce overall system cost and weight while increasing stopping capability and parking abilities, the brake calipers may incorporate a Spring Applied, Hydraulic Released (SAHR) parking function. The parking brake functionality of the caliper is created using the same frictional surface as the service brake, however the mechanism that creates the force is different. The calipers include springs that apply clamping force to the brake rotor to hold the military vehicle 1000 stationary (e.g. parking). In order to release the parking brakes, the braking system 700 applies a hydraulic force to compress the springs, which releases the clamping force. The hydraulic force to release the parking brakes comes through a secondary hydraulic circuit from the service brake hydraulic supply, and a switch on the dash actuates that force, similar to airbrake systems.

Referring specifically to the exemplary embodiment shown in FIG. 11 , braking system 700 is shown schematically to include a motor 710 having a motor inlet 712. The motor 710 is an air motor configured to be driven by an air system of military vehicle 1000, according to an exemplary embodiment. The motor 710 may be coupled to the air system of military vehicle 1000 with a line 714. As shown in FIG. 11 , braking system 700 includes a pump 720 that includes a pump inlet 722, a pump outlet 724, and a pump input shaft 726. The pump input shaft 726 is rotatably coupled to the motor 710 (e.g., an output shaft of the motor 710).

As shown in FIG. 11 , braking system 700 includes a plurality of actuators 730 coupled to the pump outlet 724. According to an exemplary embodiment, the actuators 730 includes a housing 732 that defines an inner volume and a piston 734 slidably coupled to the housing 732 and separating the inner volume into a first chamber and a second chamber. The plurality of actuators 730 each include a resilient member (e.g., spring, air chamber, etc.), shown as resilient member 736 coupled to the housing and configured to generate a biasing force (e.g., due to compression of the resilient member 736, etc.). According to an exemplary embodiment, the plurality of actuators 730 each also include a rod 738 extending through an end of the housing 732. The rod 738 is coupled at a first end to piston 734 and coupled at a second end to a brake that engages a braking member (e.g., disk, drum, etc.), shown as braking member 740. As shown in FIG. 11 , the rod is configured to apply the biasing force to the braking member 740 that is coupled to wheel and tire assemblies 600 thereby inhibiting movement of the military vehicle 1000.

According to an exemplary embodiment, a control is actuated by the operator, which opens a valve to provide air along the line 714. Pressurized air (e.g., from the air system of military vehicle 1000, etc.) drives motor 710, which engages pump 720 to flow a working fluid (e.g., hydraulic fluid) a through line 750 that couples the pump outlet 724 to the plurality of actuators 730. According to an exemplary embodiment, the pump 720 is a hydraulic pump and the actuator 730 is a hydraulic cylinder. Engagement of the pump 720 provides fluid flow through line 750 and into at least one of the first chamber and the second chamber of the plurality of actuators 730 to overcome the biasing force of resilient member 736 with a release force. The release force is related to the pressure of the fluid provided by pump 720 and the area of the piston 734. Overcoming the biasing force releases the brake thereby allowing movement of military vehicle 1000.

As shown in FIG. 11 , braking system 700 includes a valve, shown as directional control valve 760, positioned along the line 750. According to an exemplary embodiment, directional control valve 760 includes a valve body 770. The valve body 770 defines a first port 772, a second port 774, and a reservoir port 776, according to an exemplary embodiment. When valve gate 762 is in the first position (e.g., pressurized air is not applied to air pilot 766) valve gate 762 places first port 772 in fluid communication with reservoir port 776. A reservoir 780 is coupled to the reservoir port 776 with a line 752. The reservoir 780 is also coupled to the pump inlet 722 with a line 754. It should be understood that the fluid may be forced into reservoir 780 from any number of a plurality of actuators 730 by resilient member 736 (e.g., when pump 720 is no longer engaged).

According to an exemplary embodiment, the directional control valve 760 selectively couples the plurality of actuators 730 to the pump outlet 724 or reservoir 780. The directional control valve 760 includes a valve gate 762 that is moveable between a first position and a second position. According to an exemplary embodiment, the valve gate 762 is at least one of a spool and a poppet. The valve gate 762 is biased into a first position by a valve resilient member 764. According to an exemplary embodiment, the directional control valve 760 also includes an air pilot 766 positioned at a pilot end of the valve gate 762. The air pilot 766 is coupled to line 714 with a pilot line 756. Pressurized air is applied to line 714 drives motor 710 and is transmitted to air pilot 766 to overcome the biasing force of valve resilient member 764 and slide valve gate 762 into a second position. In the second position, valve gate 762 places first port 772 in fluid communication with 774 thereby allowing pressurized fluid from pump 720 to flow into actuators 730 to overcome the biasing force of resilient member 736 and allow uninhibited movement of military vehicle 1000.

Control System

Referring to FIG. 12 , the systems of the military vehicle 1000 are controlled and monitored by a control system 1200. The control system 1200 integrates and consolidates information from various vehicle subsystems and displays this information through a user interface 1201 so the operator/crew can monitor component effectiveness and control the overall system. For example, the subsystems of the military vehicle 1000 that can be controlled or monitored by the control system 1200 are the engine 300, the transmission 400, the transaxle 450, the suspension system 460, the wheels and tire assemblies 600, the braking system 700, the fuel system 800, the power generation system 900, and a trailer 1100. However, the control system 1200 is not limited to controlling or monitoring the subsystems mentioned above. A distributed control architecture of the military vehicle 1000 enables the control system 1200 process.

In one embodiment, the control system 1200 provides control for terrain and load settings. For example, the control system 1200 can automatically set driveline locks based on the terrain setting, and can adjust tire pressures to optimal pressures based on speed and load. The control system 1200 can also provide the status for the subsystems of the military vehicle 1000 through the user interface 1201. In another example, the control system 1200 can also control the suspension system 460 to allow the operator to select appropriate ride height.

The control system 1200 may also provide in-depth monitoring and status. For example, the control system 1200 may indicate on-board power, output power details, energy status, generator status, battery health, and circuit protection. This allows the crew to conduct automated checks on the subsystems without manually taking levels or leaving the safety of the military vehicle 1000.

The control system 1200 may also diagnose problems with the subsystems and provide a first level of troubleshooting. Thus, troubleshooting can be initiated without the crew having to connect external tools or leave the safety of the military vehicle 1000.

The construction and arrangements of the vehicle, as shown in the various exemplary embodiments, are illustrative only. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described herein. Some elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. The order or sequence of any process, logical algorithm, or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes, and omissions may also be made in the design, operating conditions and arrangement of the various exemplary embodiments without departing from the scope of the present invention. 

The invention claimed is:
 1. A military vehicle comprising: a front axle; a rear axle; a front differential coupled to the front axle; and a transaxle coupled to the rear axle and the front differential, the transaxle including an internal mechanical disconnect that facilitates mechanically decoupling the transaxle from the front differential.
 2. The military vehicle of claim 1, wherein the transaxle includes an input and an output on the same side thereof, wherein the input is configured to couple to a prime mover of the military vehicle and the output is coupled to the front differential.
 3. The military vehicle of claim 2, further comprising the prime mover, the prime mover including an engine and a transmission.
 4. The military vehicle of claim 1, further comprising a prime mover, wherein the front differential defines a mount to which the prime mover is coupled.
 5. The military vehicle of claim 4, wherein the prime mover includes an engine.
 6. The military vehicle of claim 1, further comprising an actuator that is accessible to facilitate engaging the internal mechanical disconnect.
 7. The military vehicle of claim 6, wherein the actuator is a mechanical air solenoid override.
 8. The military vehicle of claim 6, wherein the actuator is accessibly from an exterior of the military vehicle.
 9. The military vehicle of claim 7, wherein the actuator is positioned at a rear of the military vehicle.
 10. The military vehicle of claim 1, further comprising: a tractive element coupled to the front axle or the rear axle; and a brake system including: a brake configured to facilitate braking the tractive element; a brake housing defining an inner volume; a piston separating the inner volume into a first chamber and a second chamber; a rod extending through an end of the brake housing and coupled to the piston, the rod positioned to selectively engage with the brake to inhibit movement of the tractive element; a resilient member positioned within the inner volume and configured to generate a brake biasing force against the piston such that the rod is biased into engagement with the brake; and an air-to-hydraulic intensifier coupled to the brake housing, the air-to-hydraulic intensifier configured to receive a supply of air and provide a hydraulic fluid to the brake housing based on the supply of air to overcome the brake biasing force to disengage the rod from the brake to permit movement of the tractive element.
 11. The military vehicle of claim 10, further comprising: a valve positioned between the air-to-hydraulic intensifier and the brake housing; and a hydraulic reservoir fluidly coupled to the valve and the air-to-hydraulic intensifier; wherein the valve includes a first port fluidly coupled to the air-to-hydraulic intensifier, a second port fluidly coupled to the hydraulic reservoir, and a third port fluidly coupled to the brake housing.
 12. The military vehicle of claim 11, wherein the valve includes a valve gate that is repositionable between a first position and a second position, the first position coupling the first port to the third port to fluidly couple the air-to-hydraulic intensifier to the brake housing, the second position coupling the second port to the third port to fluidly couple the hydraulic reservoir to the brake housing.
 13. The military vehicle of claim 12, wherein the valve includes: an air pilot positioned at a first end of the valve gate; and a biasing element positioned at an opposing second end of the valve gate, the biasing element configured to provide a valve biasing force to the valve gate to bias the valve gate into the second position.
 14. The military vehicle of claim 13, wherein the brake biasing force of the resilient member is configured to bias the piston to force the hydraulic fluid out of the brake housing, through the valve, and into the hydraulic reservoir in response to the valve being in the second position.
 15. The military vehicle of claim 13, further comprising an air supply line coupled to the air-to-hydraulic intensifier and the air pilot, the air supply line configured to provide the supply of air to the air-to-hydraulic intensifier and the air pilot, wherein the supply of air provided to the air pilot overcomes the valve biasing force to reposition the valve gate into the first position to place the air-to-hydraulic intensifier into fluid communication with the brake housing to facilitate disengaging the brake.
 16. The military vehicle of claim 1, further comprising: a passenger capsule including sidewalls and a floor coupled to the sidewalls, wherein bottom edges of the sidewalls extend past and below the floor; and a belly deflector coupled to the bottom edges of the sidewalls of the passenger capsule, wherein the belly deflector is isolated from the floor of the passenger capsule.
 17. The military vehicle of claim 16, wherein the floor of the passenger capsule defines a structural tunnel having an arcuate-shaped profile extending into an interior of the passenger capsule, further comprising: energy absorbing seats positioned on opposing sides of the structural tunnel, the energy absorbing seats including a shock attenuating system; and footpads positioned beneath the energy absorbing seats and spaced from the floor.
 18. The military vehicle of claim 1, wherein the transaxle includes: a housing; a transfercase disposed within the housing; and a rear differential disposed within the housing and coupled to the transfercase.
 19. A military vehicle comprising: a front axle; a rear axle; a prime mover; a front differential coupled to the front axle; a transaxle coupled to the prime mover, the rear axle, and the front differential, the transaxle including an internal mechanical disconnect; and an actuator positioned at a rear of the military vehicle that facilitates engaging the internal mechanical disconnect to mechanically decouple the transaxle from the front differential.
 20. A military vehicle comprising: a front axle; a rear axle; a plurality of tractive elements coupled to the front axle and the rear axle; a front differential coupled to the front axle; a transaxle coupled to the rear axle and the front differential; and a brake system including: a brake configured to facilitate braking one of the plurality of tractive elements; a brake housing defining an inner volume; a piston separating the inner volume into a first chamber and a second chamber; a rod extending through an end of the brake housing and coupled to the piston, the rod positioned to selectively engage with the brake to inhibit movement of the one of the plurality of tractive elements; a resilient member positioned within the inner volume and configured to generate a brake biasing force against the piston such that the rod is biased into engagement with the brake; and an air-to-hydraulic intensifier coupled to the brake housing, the air-to-hydraulic intensifier configured to receive a supply of air and provide a hydraulic fluid to the brake housing based on the supply of air to overcome the brake biasing force to disengage the rod from the brake to permit movement of the one of the plurality of tractive elements. 